Now the university's school of medicine is coming under international pressure to lift the punishment meted out to one of its academics.

As part of what he says was an ongoing discussion on human uniqueness, Evans showed a copy of the fellatio paper to a female colleague in the school of medicine. "There was not a shred of a sign of offence taken at the time," Evans says. "She asked for a copy of the article."

A week later he got a letter informing him that he was being accused of sexual harassment. Evans says the whole case is "utterly bizarre". The complainant's side of the argument is that she was "hurt and disgusted", and asked Evans to leave a copy of the paper with her as way of cutting short the meeting.

No offence intended

It seems there was more to the grievance between Evans and the complainant than the fellatio paper incident, but an independent investigation found that Evans was not guilty of sexual harassment. The investigation stated that it was reasonable for the colleague to have been offended and that showing the paper was a joke with a sexual innuendo, but that it was not Evans' intention to cause offence.

Dennett calls the punishment "an outrageous violation of academic freedom" and Pinker says the "absurd and shameful" judgment "runs contrary to the principle of intellectual freedom and freedom of speech, to say nothing of common sense".

The paper, published last year in PLoS One, was covered in New Scientist and many other outlets. The story had a certain prurient interest, which was only heightened by an explicit video that went with it